Tractor mounted pavement washer

ABSTRACT

Disclosed is a pavement washer having two sets of spray nozzles mounted on the front of a small tractor. Nozzles of the first set are aimed ahead substantially horizontally to throw a pattern of cleaning solution well ahead of the tractor, while the second set of nozzles are aimed sharply downward as well as forward to spray a pattern of water ahead of the tractor but behind the cleaning solution. Also disclosed is an arrangement for connecting the tractor to a stationary source of water through a hose wherein provision is made to shut off the ignition of the tractor before the hose is pulled taut.

United States Patent Rudloff TRACTOR MOUNTED PAVEMENT WASHER Inventor: Robert H. Rudloff, 3205 Los Felix,

Los Angeles, Calif. 91205 Filed: Sept. 16, 1970 Appl. No.: 72,671

References Cited UNITED STATES PATENTS Lamiell et a1 ..239/ 167 Nichols ..239/163 X Harmon ..239/167 Savage et a1 ..239/163 X Perry ..239/163 51 Sept. 12, 1972 1,971,262 8/ 1934 Hendricks ..239/167 X 2,607,336 8/1952 Everts ..239/163X 3,122,323 2/1964 Wallis ..239/159X ABSTRACT Disclosed is a pavement washer having two sets of spray nozzles mounted on the front of a small tractor. Nozzles of the first set are aimed ahead substantially horizontally to throw a pattern of cleaning solution well ahead of the tractor, while the second set of nozzles are aimed sharply downward as well as forward to spray a pattern of water ahead of the tractor but behind the cleaning solution. Also. disclosed is an arrangement for connecting the tractor to a stationary source of water through a hose wherein provision is made to shut off the ignition of the tractor before the hose is pulled taut.

15 Claims, 5 Drawing Figures TRACTOR MOUNTED PAVEMENT WASHER The present invention is directed to a mobile pavement washing machine and more particularly to a tractor mounted spray head assembly-by which a cleaning solution and water are sprayed on the pavement, with the water being sprayed far enough from the cleaning solution to allow the latter to take effect before being washed away.

With the growing public acceptance of drive-in places of commerce, the importance of the parking lot and of its maintenance has also increased. This is particularly true of drive-in restaurants where cleanliness of the parking lot is desirable since people eat either in their cars parked in the lot or at tables which are outside and immediately adjacent the parking lot. Heretofore parking lots have usually been cleaned manually,

which is a time consuming, expensive, and unpleasant task. The present invention is directed to a small, modestly priced machine capable of cleaning a pavement such as a parking lot rapidly and thoroughly. In accordance with a principal feature of the invention, the pavement cleaning apparatus includes a spraying assembly mounted upon a small tractor, usually in front. The spraying assembly preferably includes at least two sets of nozzles. Through the first set of nozzles a cleaning solution, such as a mixture of a detergent and water is sprayed in a pattern well ahead of the tractor. Through the second set of nozzles water is sprayed, also ahead of the tractor but sufficiently spaced from the cleaning solution to allow the solution to have its desired cleaning effect upon the pavement before being rinsed away.

' It is desirable that, as the tractor moves ahead, all of the cleaning solution be rinsed away. Toward this end the spray pattern in which the water is discharged at the pavement is made wider than the spray pattern of the cleaning solution, with the spray pattern of water being preferably made arcuate so as to, tend to sweep inward and confine the strip of cleaning solution preceding it.

The water requirements of the pavement cleaning machine are considerable and it is most expedient to satisfy them by connecting the machine toa remote source of water through a hose rather than by carrying the necessary water supply on, or with, the tractor. Accordingly, in accordance with another feature of the invention, water is fed to the tractor from a stationary water source through a hose which is so designed that if through inadvertence the tractor should be driven too far away from the stationary water source, thereby tending to stretch the hose, this condition will be sensed and will preferably stop the tractor automatically. In keeping with this feature of the invention, at least one loop is formed in the hose and a yieldable means, such as a tension spring, is connected across the neck of that loop. Thus, as the vehicle is driven in a direction away from the stationary water source, tending to stretch the hose, the loop will be opened against the restraining force of the tension spring so that the pulling force exerted on the hose is determined initially by the strength of the spring. Sensing means, such as a limit switch, are connected across the neck of the loop in such a way that when the tension spring has been stretched to a predetermined limit, which is designed to occur before the loop has been completely straightened, the sensing means will be actuated. Advantageously, the sensing means may be a limit switch which is connected in series with the ignition of the tractor engine .so that the engine is disabled before the loop is completely straightened, thereby preventing the hose from being damaged. I

To prevent the water hose from interfering with the operation of the tractor, the hose is connected thereto by means of a horizontally swiveling pipe carried at the rear of the tractor. The range of travel of the swiveling pipe is limited by a pair of stops so as to insure that the pipe points either to the rear or to the side of the tractor, thereby keeping the hose out of its way. Preferably, the loop which is provided for stress relief is formed immediately at the point where the hose joins the swiveling pipe and the pipe extends horizontally at a sufficient height above the pavement to prevent the loop from dragging along the ground.

The invention may be more clearly understood from the following detailed description when taken in conjunction with the appended claims and the accompanying drawings wherein:

FIG. 1 is a perspective view of a tractor mounted pavement washer incorporating features of the present invention;

FIG. 2 is a front view of the tractor mounted pavement washer illustrated in FIG. 1;

FIG. 3 is a side view, partially cut away, of the front portion of the pavement washer illustrated in FIG. 1 showing in particular thelocation of the water pump and detergent injector carried by the tractor;

- FIG. 4 is a perspective view of a spray head of the type used to direct a water rinse at the pavement; and

FIG. 5 is a side view of the tractor mounted pavement washer illustrating the spacing between the spray patterns of cleaning solution and rinsing water and also showing the hose arrangement for supplying water to the tractor.

An exemplary embodiment of a tractor mounted pavement washer incorporating features of the present invention is illustrated in FIG. 1. The tractor 10 may be a commercially available type in which a four wheeled chassis 11 is powered by a gasoline engine 13 and controlled by means of a steering wheel 15, a gearshift lever 17, a brake pedal 19, and other controls not shown, by an operator positioned on a seat 21. Mounted on the front of the tractor is a spray head assembly comprised principally of a first set of spray nozzles 23 and a second set of spray nozzles 25 and 27. Serving to discharge a cleaning solution, the first set of spray nozzles are anchored in and supplied through a manifold 29 which, for sake of easy replacement, is comprised of two symmetrical halves 29a and 29b. Each of the manifold halves 29a and 29b are threaded at one end and are screwed into a common coupling as best seen in FIG. 2. A second manifold 33, also comprised of two halves 33a and 33b, extends under the first manifold 29 and serves to support, and supply water to, the second set of spray nozzles 25 and 27. Again, for sake of easy replaceability, the second manifold 33 is made of two symmetrical sections, with one end of each section being threaded into a common coupling 35. The couplings 31 and 35 permit replacement of the manifold sections 29a and 29b, and 33a and 33b not only with identical components, as would be the case in the event that the replaced part is damaged, but also with longer or shorter sections in the event that a different width of spray pattern is desired.

The manifolds 29 and 33 are rigidly connected to form a single assembly by means of a pair of horizontally spaced, vertically extending brackets 37 and 39 upon which they are mounted by a set of U-clamps 41. The entire .spray head assembly, comprised of the manifolds 29 and 33, the spray heads 23, 25 and 27 mounted thereon and the brackets 37 and 39, is attached to the front of the tractor by suitable means which include a pair of side braces 43 bolted to the front fenders of the tractor 10.

Water is supplied to the spray nozzles 25 and 27 from a remote, stationary source of water shown as the tap 28 through a flexible hose 43 attached to the back of the tractor 10. In order to prevent interference with the operation of the tractor, the end of the hose 43 is connected to pipe assembly 45 having a horizontally extending portion 45a and a short vertical end portion 45b rotatably received in a coupling 47 in such a manner as to permit the horizontal pipe portion 45a to swivel from one side of the tractor to the other in a horizontal plane. A pair of stops 49 and 51 bolted on opposite sides of the tractor 10 at its rear extend upwardly to limit the motion of the pipe portion 45a to approximately 180 of arc, thereby preventing the pipe portion 45a and the hose 43 attached to it from swinging past the rear wheels of the tractor. Cross braces 50 and 52 which extend horizontally between the stops 49 and 51 serve to help maintain them rigidly upright and also serve as a mounting platform for a vertically ex- I tending pipe 54 upon which the coupling 47 is secured.

To supply the necessary water pressure at the nozzles 25 and 27 the water received through the hose 43 and the pipe assembly 45 is first fed to a water pump 53 (see FIG. 3) through a short length of heavy water hose 55 which is connectedbetween the pump 53 and the pipe 54 under the coupling 47. From the pump 53 water at the desired pressure is fed through a pipe 57 to the inlet of a coupling 59 having an upper and a lower outlet port 59a and 59b. The lower outlet port 59b of the coupling 59 is connected by a short length of pipe 61 to the coupling 35 which connects the two halves of the water discharge manifold 33. The upper outlet port 59a of the coupling 59 is similarly connected through a short piece of pipe 63 to the water inlet port 65a of an injector whose function is to supply the upper set of spray nozzles 23 with a cleaning solution, e.g. comprised of adetergent and water. The water is supplied to the injector 65 from the pump 53 and through the coupling 59 as just described. The detergent of other pavement cleaning chemical is carried on the tractor 10 in a non-pressurized tank 67 which is vented to the atmosphere and connected through a suitable line .69 to a second inlet port 65b of the injector 65. The injector 65 has an outlet port, indicated at 650, where a mixture of the detergent received through the line 69 and water received through the coupling 59 is discharged under pressure. The injector outlet 65c is connected through a pipe section 71 to an inlet of the coupling 31 through which the solution is distributed to the two halves of the upper manifold 29.

Injectors of the type suitable for use with the present invention are well known. One which was found to operate satisfactorily is manufactured by the Dema Engineering Company of St. Louis, Mo. under its model 200 series. In operation, water is supplied under pressure by the pump 53 directly to the spray nozzles 25 and 27 and to the water inlet port 65a of the injector 65. In a manner which need not be understood for purposes of explaining the present invention, a vacuum is created in the injector 65 by the rapid flow of water through the water inlet port 65a and this vacuum has the effect of pulling detergent from the tank 67 through the inlet port 65b into the injector 65, where it is mixed in a predetermined proportion with water. The waterdetergent mixture is expelled through the injector outlet port 65c and is fed to the manifold 29. Means, not shown, are provided on the injector 65 to adjust the richness of the water-detergent mixture. 9

In addition to serving as a source of cleaning solution for the spray nozzles 23, the injector 65 may also be used to supply the cleaning solution to additional accessories, such as hand operated washing-brushes of the type having an opening through which a cleaning solution is dispensed during use. Where this feature is desired, a standard threaded up would be provided on the pipe section 71 which is connected to the output port of the injector 65. Shut-off valves would be interposed respectively between the tap andthe coupling 31 and between the coupling 59 and the coupling 35 in order to permit use of the accessory when the tractor is not being used for pavement cleaning.

It is an important aspect of the invention that a cleaning solution and water are deposited on the pavement to be cleaned in two patterns 22 and 24 (see FIG. 5) which are spaced apart sufficiently .to permit the cleaning solution to take effect before it is rinsed away by the water. Toward this end the spray nozzles 23 are supported relatively high above the pavement to be cleaned and are aimed to spray substantially directly forward that is, within 15 of horizontal in order to project the cleaning solution a substantial distance ahead of the tractorl0. In contrast, the spray nozzles 25 and 27, which serve to direct rinsing water at the pavement, are mounted relatively close to the pavement and are directed at it at a fairly sharp angle, of the order of from vertical. This has the effect of reducing the distance to which the water is projected forward from the tractor 10 and also serves to increase the force with which the water strikes the pavement. Accordingly, the water pattern produced by the apparatus of the present invention impinges sufficiently far behind the pattern of cleaning solution to allow the latter to take effect and at the same time the water pattern strikes the pavement with considerable force, thereby enhancing further the cleaning effectiveness of the unit.

The preferred distance between the cleaning solution spray pattern 22 and the rinsing water spray pattern 24 will vary with the length of time it is desired that the cleaning solution have to act upon the pavement and upon the speed with which it is expected that the tractor 10 will be driven. However, in order to insure that the cleaning solution will not be washed away prematurely, it is desirable that there be some separation between the two spray patterns, i.e. that they do not overlap. In some instances, either or both of the manifolds 29, 33 may be arranged for vertical adjustment to adjust the separation between patterns.

A spray nozzle of the type found suitable for use on the lower manifold 33 for dispensing water is shown in FIG. 4 and is manufactured by Spraying Systems Co. of Delwood, III. as Model l/4 P5010. At a pressure of 40 pounds per square inch the spray characteristics of the particular nozzle used were such as to project water at the pavement in a flat, fanshaped spray pattern at a 30 included angle with the pavement and with the spray angle being 50, as shown in FIGS. 3 and 4. The spray nozzles 23 preferably are spaced so as to produce a single substantially continuous pattern across the front of the tractor 10. v

It has been found advantageous to make the combined water spray pattern produced by the nozzles 25 and 27 wider than the cleaning solution pattern laid down by the spray nozzles 23 and to space the nozzles 25 and 27 to produce a single continuous spray pattern extending transversely across the tractor in order that all of the cleaning solution be rinsed away by the water. For this reason the lower manifold 33 is made longer than the upper manifold 29 and is provided with a larger number of spray nozzles 25 and 27. In addition, it has been found particularly effective to distribute the rinsing water in a pattern such that the strip of cleaning solution will be confined by the edges of the rinsing water rather than being forced by it to flow out of the path of the rinsing water. For this purpose, the ends of the lower manifold 33 are angled forward, with a spray nozzle 27 being mounted at each such forwardly angled end. As a result, the spray pattern discharged by the end nozzles 27 is directed partially inward, toward the central part of the water spray pattern produced by the spray nozzles 25, thus providing a water spray pattern as shown in FIG. 1, which for convenience in terminology can be called arcuate or convex. It has been found satisfactory to use the same type spray nozzle as that which is used for the central water spray nozzles 25, although one with a wider spray angle might be used to advantage where it .is desired to extend the curved edges of the water spray pattern.

An alternative spray pattern may be used with the pavement washer of the present invention where it is desired that the cleaning solution remain on the pavement for a particularly long time before being rinsed away. With this spray pattern the cleaning solution pattern is directed to one side of the water pattern. Thus with each pass of the tractor two strips will be sprayed side by side, one of cleaning solution and one of water. And as each strip of cleaning solution is being washed off the pavement by the adjacent spray pattern of water, during successive passes with the tractor another strip of cleaning solution is being laid down and will not be rinsed off until the following pass. For this purpose, the upper manifold 29 may be arranged to provide adjustment in the direction of spray from the detergent nozzles 23.

In order to reduce the risk of tearing the pipe 43 due to inadvertently driving the tractor 10 beyond the reach of the hose 43, means are provided to give an immediate waming when the reach of the hose 43 has been approached and before the hose breaks. Specifically, a loop 71 is formed in the hose 43 near the swiveling pipe portion 45 and the ends of the loop are yieldably connected through a tension spring 73 which is connected across the neck of the loop 71. Also connected across the neck of the loop 71 is a cord 75 whose one end is connected to one end of the loop 71 at 71a and whose opposite end is connected to a switch 77 mounted on the pipe 45a near the other end 71b of the loop 71. In a manner not shown, the switch 77 is connected in series with the ignition system of the tractor engine 13 so that when the cord is pulled the switch 77 opens and the ignition system of the motor 13 is temporarily interrupted, thus stopping the motor. The length of the cord 75 is selected so that, as the tractor 10 is driven to the limit of the hose 23 and begins to open the loop 71 against the force of the spring 73, the cord 75 is pulled tight before the loop 71 itself is completely straightened. Consequently, the'switch 77 will be actuated and the tractor will be stopped while there is still some slack left in the loop 71 of the hose 23 and before the hose is damaged. If desired, an additional loop 79 may be provided in the hose 43 with a tension spring 81 connected across the second loop.

In some cases the pipe assembly 45 and the hose 43 with its associated, accessories may be replaced by a water tank carried on or with the tractor 10. Where the amount'of water required is moderate, the tank may be carried on the tractor itself. A greater water requirement could be satisfied by providing a separate, towable water tank hitched to the back of the tractor.

What is claimed is:

1. A pavement cleaning machine comprising in combination:

a. avehicle;

b. a first set of spray nozzles extending transversely across the front of said vehicle and connected to a source of pavement treating solution and mounted on said vehicle in an array shaped to direct said solution at said pavement in a first pattern ahead of said vehicle as said vehicle travels; and

. a second set of spray nozzles extending transversely across said vehicle and connected to a source of Y water and mountedv on said vehicle in an array shaped to direct said water at said pavement in a second pattern spaced in non-overlapping relationship behind said first pattern and being aimed forward and toward the ground to sweep the pavement with water for rinsing said solution from the pavement, said first and second sets of nozzles being operated at the same time.

2. A pavement cleaning machine in accordance with claim 1 and further characterized by the second pattern being wider than the first pattern and being inwardly aimed at its ends into an arcuate shape so as to confine said solution to the pavement covered by said second pattern during the travel of said vehicle.

3. A pavement cleaning machine in accordance with claim 1 wherein at least one of said first and second set of spray nozzles is carried on a manifold comprised of two pipes removably extending in opposite directions from a common threaded pipe coupling.

4. A pavement cleaning machine comprising in combination:

a. a self-powered vehicle;

b. a first set of spray nozzles connected to a source of pavement treating solution and mounted on said vehicle in an array shaped to direct said solution at said pavement in a first pattern;

. a second set of spray nozzles connected to a source of water and mounted on said vehicle in an array shaped to direct said water at said pavement in a second pattern spaced in non-overlapping relationship with said first pattern for rinsing said solution from the pavement;

d. a hose for supplying water to said second set of nozzles from said source of water;

e. a tension spring connecting portions of said hose so as to form a loop therein; and

f. sensing means connected across the neck of said loop and electrically connected to disable said vehicle when said tension spring has been stretched to a predetermined length.

5. A pavement cleaning machine comprising in combination:

a. a self-powered vehicle;

b. a first set of spray nozzlesconnected to a source of pavement treating solution and, mounted on said vehicle in an array shaped to direct said solution at said pavement in a first pattern;

. a second set of spray nozzles connected to a source of water and mounted on said vehicle in an array shaped to direct said water at said pavement in a second pattern spaced in non-overlapping relationship with said first pattern for rinsing said solution from the pavement;

of said vehicle in a pipe coupling member, said pipe assembly having a horizontally extending portion swiveling in a horizontal plane about a verticle axis defined by said pipe coupling member;

means for connecting said pipe coupling member to said second set of nozzles; and

f. a hose connected between said horizontally extending portion and said source of water.

6. A pavement cleaning machine comprising in combination:

a. a vehicle;

b. a tank mounted on said vehicle for holding a pave- 'ment cleaning chemical;

c. means on said vehicle for connecting to a source of water; I

an injector having a first inlet connected to receive chemical from said tank, a second inlet connected to receive water from said source and an outlet for dispensing a solution of said chemical and said water;

. a first set of spray nozzles connected to receive said solution from said injector outlet and mounted on the front of said vehicle in an array shaped to direct said solution at said pavement in a first pattern; and

f. a second set of spray nozzles connected to receive water from said source and mounted on the front of said vehicle in an array shaped to direct water at said pavement in non-overlapping relation with said first pattern for rinsing said solution from the pavement.

7. A pavement cleaning machine in accordance with claim 6 wherein said means for connecting to a source of water includes a pump on the vehicle for increasing the water pressure.

8. A pavement cleaning machine in accordance with a pipe assembly rotatably mounted upon the rear with claim 6 and further characterized in that said first and second set of nozzles are respectively supported by upper and lower manifolds rigidly mounted transversely across the front of said vehicle, said first set of nozzles being aimed a substantial distance ahead of said machine, and said second set of nozzles being aimed toward the pavement closely in front of the machine.

11. A pavement cleaning machine in accordance with claim 10 wherein said second set of nozzles are spaced so as to produce a single continuous spray pattern extending across the front of the vehicle.

12. A pavement cleaning machine in accordance with claim 11, wherein saidsecond manifold has ends which extend past the ends of said first manifold and extend forwardly with the end nozzles on the second manifold directed toward the central part of the water spray pattern to confine said solution.

13. For spraying a cleaning solution and water onto a pavement from a self-powered vehicle, a spray head assembly comprising in combination:

a. first and second sets of spray nozzles mounted on a common framework; means for attaching said framework to the front of said vehicle, said first and second sets of spray nozzles being respectively aimed to deposit said solution and water in a first and a second pattern in front of said vehicle when the framework is so attached, said first pattern being non-overlapping spaced from said second pattern;

c. said first and second sets of nozzles being respectively supported by first and second spray bars extending transversely across the front of said vehicle, the first spray bar being mounted above the second spray bar, with its nozzles aimed substantially horizontally forward so as to deposit a ribbon of said solution ahead of said vehicle as said vehicle travels and the nozzles of the second set being aimed forward and toward the ground to sweep said pavement with water.

14. A spray head assembly in accordance with claim 13 and characterized further in that said second spray bar is longer than said first spray bar, and has a nozzle at each of its ends which extend forward so as to produce an arcuate spray pattern which sweeps the edges of said ribbon of solution toward each other.

15. A spray head assembly in accordance with claim 13 and characterized further in that each of said spray bars is comprised of two symmetrical sections threaded at one end and removably fitted into opposite sides of a common coupling. 

1. A pavement cleaning machine comprising in combination: a. a vehicle; b. a first set of spray nozzles extending transversely across the front of said vehicle and connected to a source of pavement treating solution and mounted on said vehicle in an array shaped to direct said solution at said pavement in a first pattern ahead of said vehicle as said vehicle travels; and c. a second set of spray nozzles extending transversely across said vehicle and connected to a source of water and mounted on said vehicle in an array shaped to direct said water at said pavement in a second pattern spaced in non-overlapping relationship behind said first pattern and being aimed forward and toward the ground to sweep the pavement with water for rinsing said solution from the pavement, said first and second sets of nozzles being operated at the same time.
 2. A pavement cleaning machine in accordance with claim 1 and further characterized by the second pattern being wider than the first pattern and being inwardly aimed at its ends into an arcuate shape so as to confine said solution to the pavement covered by said second pattern during the travel of said vehicle.
 3. A pavement cleaning machine in accordance with claim 1 wherein at least one of said first and second set of spray nozzles is carried on a manifold comprised of two pipes removably extending in opposite directions from a common threaded pipe coupling.
 4. A pavement cleaning machine comprising in combination: a. a self-powered vehicle; b. a first set of spray nozzles connected to a source of pavement treating solution and mounted on said vehicle in an array shaped to direct said solution at said pavement in a first pattern; c. a second set of spray nozzles connected to a source of water and mounted on said vehicle in an array shaped to direct said water at said pavement in a second pattern spaced in non-overlapping relationship with said first pattern for rinsing said solution from the pavement; d. a hose for supplying water to said second set of nozzles from said source of water; e. a tension spring connecting portions of said hose so as to form a loop therein; and f. sensing means connected across the neck of said loop and electrically connected to disable said vehicle when said tension spring has been stretched to a predetermined length.
 5. A pavement cleaning machine comprising in combination: a. a self-powered vehicle; b. a first set of spray nozzles connected to a source of pavement treating solution and mounted on said vehicle in an array shaped to direct said solution at said pavement in a first pattern; c. a second set of spray nozzles connected to a source of water and mounted on said vehicle in an array shaped to direct said water at said pavement in a second pattern spaced in non-overlapping relationship with said first pattern for rinsing said solution from the pavement; d. a pipe assembly rotatably mounted upon the rear of said vehicle in a pipe coupling member, said pipe assembly having a horizontally extending portion swiveling in a horizontal plane about a verticle axis defined by said pipe coupling member; e. means for connecting said pipe coupling member to said second set of nozzles; and f. a hose connected between said horizontally extending portion and said source of water.
 6. A pavement cleaning machine comprising in combination: a. a vehicle; b. a tank mounted on said vehicle for holding a pavement cleaning chemical; c. means on said vehicle for connecting to a source of water; d. an injector having a first inlet connected to receive chemical from said tank, a second inlet connected to receive water from said source and an outlet for dispensing a solution of said chemical and said water; e. a first set of spray nozzles connected to receive said solution from said injector outlet and mounted on the front of said vehicle in an array shaped to direct said solution at said pavement in a first pattern; and f. a second set of spray nozzles connected to receive water from said source and mounted on the front of said vehicle in an array shaped to direct water at said pavement in non-overlapping relation with said first pattern for rinsing said solution from the pavement.
 7. A pavement cleaning machine in accordance with claim 6 wherein said means for connecting to a source of water includes a pump on the vehicle for increasing the water pressure.
 8. A pavement cleaning machine in accordance with claim 6 wherein said vehicle includes a seat and controls for operation by an operator positioned on the seat.
 9. A pavement cleaning machine in accordance with claim 6 wherein said tank is non-pressurized and vented to the atmosphere.
 10. A pavement cleaning machine in accordance with claim 6 and further characterized in that said first and second set of nozzles are respectively supported by upper and lower manifolds rigidly mounted transversely across the front of said vehicle, said first set of nozzles being aimed a substantial distance ahead of said machine, and said second set of nozzles being aimed toward the pavement closely in front of the machine.
 11. A pavement cleaning machine in accordance with claim 10 wherein said second set of nozzles are spaced so as to produce a single continuous spray pattern extending across the front of the vehicle.
 12. A pavement cleaning machine in accordance with claim 11, wherein said second manifold has ends which extend past the ends of said first manifold and extend forwardly with the end nozzles on the second manifold directed toward the central part of the water spray pattern to confine said solution.
 13. For spraying a cleaning solution and water onto a pavement from a self-powered vehicle, a spray head assembly comprising in combination: a. first and second sets of spray nozzles mounted on a common framework; b. means for attaching said framework to the front of said vehicle, said first and second sets of spray nozzles being respectively aimed to deposit said solution and water in a first and a second pattern in front of said vehicle when the framework is so attached, said first pattern being non-overlapping spaced from said second pattern; c. said first and second sets of nozzles being respectively supported by first and second spray bars extending transversely across the front of said vehicle, the first spray bar being mounted above the second spray bar, with its nozzles aimed substantially horizontally forward so as to deposit a ribbon of said solution ahead of said vehicle as said vehicle travels and the nozzles of the second set being aimed forward and toward the ground to sweep said pavement with water.
 14. A spray head assembly in accordance with claim 13 and characterized further in that said second spray bar is longer than said first spray bar, and has a nozzle at each of its ends which extend forward so as to produce an arcuate spray pattern which sweeps the edges of said ribbon of solution toward each other.
 15. A spray head assembly in accordance with claim 13 and characterized further in that each of said spray bars is comprised of two symmetrical sections threaded at one end and removably fitted into opposite sides of a common coupling. 